OK hear me out cause I know this sounds like that episode of black mirror. I have a it thought out like this...

1. You must be over 18 to participate
2. You must be assessed once a month by a PT
3. You must be assessed once a month by a GP (Bloods to assess all levels and make sure you aren't harming yourself)
4. If you're caught doping you are banned and go under a three strikes policy. Strike one, ban for six months. Strike two, ban for twelve months and lose your earnings for that year. Strike three, permanent ban, forfeit all earnings under the program including any you spent and prison sentence of no less than 1 year.
5. Your heaviest weight x 1000 = your yearly earnings (e.g. 140kg deadlift x 1000 = $140,000)
6. You have a minimum amount of cardio to do an you lose $1000 for every cardio goal under your requirement.
7. You are still required to pay taxes but it is at a flat rate
8. You may enter independent competitions, and can be endorsed by private companies, but you must donate 15% of all extra earnings to charity and are still required to pay taxes on all earnings not donated